• Authors:
    • Liebig, M. A.
    • Caesar-TonThat, T.
    • Stevens, W. B.
    • Sainju, U. M.
  • Source: Journal of Environmental Quality
  • Volume: 41
  • Issue: 6
  • Year: 2012
  • Summary: Management practices, such as irrigation, tillage, cropping system, and N fertilization, may influence soil greenhouse gas (GHG) emissions. We quantified the effects of irrigation, tillage, crop rotation, and N fertilization on soil CO2, N2O, and CH4 emissions from March to November, 2008 to 2011 in a Lihen sandy loam in western North Dakota. Treatments were two irrigation practices (irrigated and nonirrigated) and five cropping systems (conventional-tilled malt barley [Hordeum vulgaris L.] with N fertilizer [CT-N], conventional-tilled malt barley with no N fertilizer [CT-C], no-tilled malt barley pea [Pisum sativum L.] with N fertilizer [NT-PN], no-tilled malt barley with N fertilizer [NT-N], and no-tilled malt barley with no N fertilizer [NT-C]). The GHG fluxes varied with date of sampling and peaked immediately after precipitation, irrigation, and/or N fertilization events during increased soil temperature. Both CO2 and N2O fluxes were greater in CT-N under the irrigated condition, but CH4 uptake was greater in NT-PN under the nonirrigated condition than in other treatments. Although tillage and N fertilization increased CO2 and N2O fluxes by 8 to 30%, N fertilization and monocropping reduced CH, uptake by 39 to 40%. The NT-PN, regardless of irrigation, might mitigate GHG emissions by reducing CO2 and N2O emissions and increasing CH4 uptake relative to other treatments. To account for global warming potential for such a practice, information on productions associated with CO2 emissions along with N2O and CH4 fluxes is needed.
  • Authors:
    • Das, S. N.
    • Venkanna, R.
    • Nikhil, G. N.
    • Swamy, Y. V.
    • Chaudhury, G. Roy
  • Source: Atmósfera
  • Volume: 25
  • Issue: 1
  • Year: 2012
  • Summary: Methane (CH4) and nitrous oxide(N2O)emission estimates were made for Vigna mango and Vigna radiata legumes. The affecting soil parameters like redox potential, soil temperature were studied to evaluate CH4 and N2O emissions. The CH4 was negative and N2O was positive for Vigna mungo, almost throughout the cropping period. The redox potential was more than +100 mV during the entire cropping period with a maximum N2O flux of 11.67 mu g m(-2) h(-1). The raise in soil temperature and the redox potential during harvest further increased the N2O flux to 18.38 mu g m(-2) h(-1). The seasonally integrated flux E((SIF)) for CH4 and N2O for Vigna mungo was calculated to be -4.06 g.m(-2) and 3.38 mg m(-2) respectively. Similarly E((SIF))values estimated for Vigna radiata cropping season were 0.009 g m(-2) and -7.6 mg m-2, whereas for the post harvesting period the fluxes were 0.02 g m(-2) and 4.06 mg m(-2) for CH4 and N2O respectively. The soil parameters like organic carbon and nutrients such as ammonia, nitrate and nitrite during the cropping season were evaluated. The emission of greenhouse gases (GHG) was also correlated to various physicochemical parameters of soil.
  • Authors:
    • Jensen, C. R.
    • Jacobsen, S. -E
    • Liu, F.
  • Source: Field Crops Research
  • Volume: 128
  • Year: 2012
  • Summary: The aim of the present review is to highlight the possibilities of a sustainable crop production in the arid Mediterranean region, which is predicted to suffer from increasingly severe droughts in the future due to climate changes, in addition to increased problems with soil salinity and increased temperatures. Annual rainfall in the region varies between 300 and 1000 mm, covering arid, semi-arid and wet ecosystems. As stress factors often act together, it is important sometimes to focus on multiple stresses affecting the crop, instead of looking at the individual stress separated from the rest. The rainfed farming systems are the most important in the Mediterranean countries. The question is if we can overcome mild to medium level of abiotic stresses by agronomic means. It might be done by using different crops of increased drought and salinity tolerance, and utilizing their stress adaptation mechanisms to optimize crop productivity. However supplemental irrigation used as deficit irrigation has the potential to overcome periods of low rainfall or high temperatures. It is suggested that improvements in crop production may arise from several strategies such as early sowing enabled by minimum tillage, increased use of organic manure, and an efficient weed control. Further, crop rotations will play an important role in improving weed control, minimizing disease risk, and increasing nitrogen availability. Introduction of drought and salt tolerant crop species as quinoa, amaranth and Andean lupin may result in more resilient crop rotations and high value cash crop products. Genotypic increases may arise from selection for early vigour, deep roots, increased transpiration efficiency, improved disease resistance, and high assimilate storage and remobilization. A range of crop and management strategies might be combined for a specific target environment in order to optimize crop productivity. These combinations can then be used as a guidance to future decision support systems for crop production at limited water supply under arid Mediterranean conditions. (C) 2011 Elsevier B.V. All rights reserved.
  • Authors:
    • Nariya, J. N.
    • Khanpara, M. D.
    • Butani, A. M.
    • Kapadiya, H. J.
  • Source: Journal of Cotton Research and Development
  • Volume: 26
  • Issue: 1
  • Year: 2012
  • Summary: FLD's with participation of farmers' in production technology was conducted in seven districts of Saurashtra. Thirty four, 50 and 50 farmers were selected for FLD's during 2005-2006, 2006-2007 and 2007-2008, respectively. Varietal, fertilizer, irrigation and inter cropping components were conducted in FLD's. Results indicated that 8.83 per cent average seed cotton yield was increased over improved varieties. In fertilizer components, there was no effect of DAP on seed cotton yield, however without DAP clearly showed the average saving of Rs. 1743/ha. The reduction of 3.98 per cent seed cotton yield was recorded in alternate furrow irrigation, but the cost of cultivation of Rs. 3370/ha was decreased as compared to local practices. In inter cropping practices, 10.13 per cent seed cotton yield was increased over local practices. Overall results clearly indicated that an additional net return of Rs. 5130, 3831, 1002 and 859 was recorded in improved varities, intercropping, irrigation and fertilizer components, respectively. Looking to the over all of three years average results with four improved production technologies of FLD's, recorded a increase of 4.6 per cent in seed cotton yield, reduced by 3.12 per cent in cost of cultivation and increased net return of 9.95 per cent with a net profit of 3371 Rs/ha during three years of cropping season.
  • Authors:
    • Rajput, T. B. S.
    • Sarangi, A.
    • Singh, M.
    • Abedinpour, M.
    • Pathak, H.
    • Ahmad, T.
  • Source: Agricultural Water Management
  • Volume: 110
  • Year: 2012
  • Summary: Crop growth simulation models of varying complexity have been developed for predicting the effects of soil, water and nutrients on grain and biomass yields and water productivity of different crops. These models are calibrated and validated for a given region using the data generated from field experiments. In this study, a water-driven crop model AquaCrop, developed by FAO was calibrated and validated for maize crop under varying irrigation and nitrogen regimes. The experiment was conducted at the research farm of the Water Technology Centre, IARI, New Delhi during kharif 2009 and 2010. Calibration was done using the data of 2009 and validation with the data of 2010. Irrigation applications comprised rainfed, i.e. no irrigation (W 1) irrigation at 50% of field capacity (FC) (W 2) at 75% FC (W 3) and full irrigation (W 4). Nitrogen application levels were no nitrogen (N 1), 75 kg ha -1 (N 2) and 150 kg ha -1 (N 3). Model efficiency ( E), coefficient of determination ( R2), Root Mean Square error (RMSE) and Mean Absolute Error (MAE) were used to test the model performance. The model was calibrated for simulating maize grain and biomass yield for all treatment levels with the prediction error statistics 0.95
  • Authors:
    • Brainard, D.
  • Source: Acta Horticulturae
  • Issue: 950
  • Year: 2012
  • Summary: In response to declines in yield and stand longevity, Michigan asparagus growers are experimenting with multiple cultural practices including irrigation, shallow tillage, and "living-mulches" sown immediately following harvest in late June. Drought stress may play an important role in limiting fern growth and increasing fern susceptibility to pests. Living mulches are thought to reduce soil degradation and suppress weeds, but may also suppress asparagus through competition for water. Research was initiated in Hart, Michigan, USA, in 2008 with the following long-term objectives: (1) to evaluate the effects of irrigation on asparagus yields and weed management under two cropping systems; and (2) to determine the effects of cereal rye ( Secale cereal) living-mulch on soil moisture, weed growth, and asparagus yield. In a research farm field experiment, 4 treatments were examined: (1) no-till with standard herbicides; (2) no-till with standard herbicides plus irrigation; (3) shallow-tillage with rye living-mulch; (4) shallow tillage with rye living-mulch plus irrigation. Irrigation increased weed density and weed dry weight but had no detectable effect on asparagus yields. Rye living mulch (1) reduced soil volumetric water content by approximately 2-3% at 60 cm; (2) suppressed weeds compared to weedy control treatments, but resulted in increased weed density and dry weight compared to conventional herbicide treatments; and (3) had no detectable effect on asparagus yield.
  • Authors:
    • Oweis, T.
    • Karrou, M.
  • Source: Agricultural Water Management
  • Volume: 107
  • Year: 2012
  • Summary: Selecting appropriate crops and applying deficit irrigation can help increase water productivity in water-limited regions such as the Mediterranean. The objective of this study was to develop water production functions of major cereal and legume crops under the same environmental and management conditions. Bread and durum wheat, faba bean, chickpea, and lentil were grown under full supplemental irrigation (FSI), two deficit irrigations levels of 2/3 of FSI (2/3SI) and 1/3 of FSI (1/3SI), and under rainfed conditions (no irrigation). In average, the actual evapotranspirations (ETs) under FSI were 549, 552, 365, 451 and 297 mm, for bread wheat, durum wheat, faba bean, chickpea and lentil, respectively. For the same crops, they were 463, 458, 330, 393 and 277 mm for the treatment 2/3SI and 357, 351, 265, 318 and 244 mm for the treatment 1/3SI, respectively. In the case of the rainfed treatment, ETs for the mentioned crops were 250, 251, 227, 237 and 215 mm, respectively. The experiment was conducted at the ICARDA experimental station at Tel Hadya, near Aleppo, Syria, over three growing seasons from 2007 to 2010. Results showed that, in general, the treatment with 1/3 of FSI gave the highest rate of increase in grain yield and water productivity. The mean grain yield from rainfed, 1/3SI, 2/3SI, and FSI were 1.36, 3.82, 5.18, and 5.70 t/ha for bread wheat; 1.24, 3.80, 5.10, and 5.75 t/ha for durum wheat; 1.57, 2.35, 2.86, and 3.54 t/ha for faba bean, 1.36, 2.63, 3.36, and 3.74 t/ha for chickpea, and 0.64, 1.16, 1.42, and 1.58 t/ha for lentil respectively. Grain yield reductions due to the application of 2/3SI were around 10, 5, 15.6, and 10.2% of FSI on average for wheat, chickpea, faba bean, and lentils, respectively. Deficit irrigation at 2/3SI increased water productivity compared to rainfed treatments, by 200, 223, 126, 148 and 190% for bread wheat, durum wheat, faba bean, chickpea, and lentils, respectively. However, differences in total water productivity of crops grown under full irrigation compared to deficit irrigation were not significant. Irrigation water productivity ranged from 25 kg ha -1 mm -1 in wheat with 1/3SI to 10 kg ha -1 mm -1 for legumes under the FSI treatment. Unlike legumes, maximizing wheat grain yield caused a decline in water productivity.
  • Authors:
    • Kutu, F. R.
  • Source: African Journal of Agricultural Research
  • Volume: 7
  • Issue: 26
  • Year: 2012
  • Summary: Conservation agriculture experiment was conducted under irrigated and dryland conditions during 2007/2008-summer cropping season to determine a suitable soil-crop management practice for increase maize yield. The study consisted of tillage practices (conventional, minimum and zero), cropping systems (sole and intercrop plots) and fertilizer regimes (unfertilized control, low, adjusted low and optimum) as treatments. Minimum and zero tillage practices constituted the conservation agriculture tillage practices while supplementation of low fertilizer rate with seed inoculation using growth enhancing microbial inoculant constituted the adjusted low fertilizer rate. Fertilizer application gave a significant (P
  • Authors:
    • Thomashow, L. S.
    • Parejko, J. A.
    • Mavrodi, D. V.
    • Mavrodi, O. V.
    • Weller, D. M.
  • Source: Applied and Environmental Microbiology
  • Volume: 78
  • Issue: 9
  • Year: 2012
  • Summary: This work determined the impact of irrigation on the seasonal dynamics of populations of Pseudomonas spp. producing the antibiotics phenazine-1-carboxylic acid (Phz +) and 2,4-diacetylphloroglucinol (Phl +) in the rhizosphere of wheat grown in the low-precipitation zone (150 to 300 mm annually) of the Columbia Plateau of the Inland Pacific Northwest. Population sizes and plant colonization frequencies of Phz + and Phl +Pseudomonas spp. were determined in winter and spring wheat collected during the growing seasons from 2008 to 2009 from selected commercial dryland and irrigated fields in central Washington State. Only Phz + bacteria were detected on dryland winter wheat, with populations ranging from 4.8 to 6.3 log CFU g -1 of root and rhizosphere colonization frequencies of 67 to 100%. The ranges of population densities of Phl + and Phz +Pseudomonas spp. recovered from wheat grown under irrigation were similar, but 58 to 100% of root systems were colonized by Phl + bacteria whereas only 8 to 50% of plants harbored Phz + bacteria. In addition, Phz +Pseudomonas spp. were abundant in the rhizosphere of native plant species growing in nonirrigated areas adjacent to the sampled dryland wheat fields. This is the first report that documents the impact of irrigation on indigenous populations of two closely related groups of antibiotic-producing pseudomonads that coinhabit the rhizosphere of an economically important cereal crop. These results demonstrate how crop management practices can influence indigenous populations of antibiotic-producing pseudomonads with the capacity to suppress soilborne diseases of wheat.
  • Authors:
    • Gitelson, A. A.
    • Peng, Y.
  • Source: Remote Sensing of Environment
  • Volume: 117
  • Issue: 440–448
  • Year: 2012
  • Summary: The synoptic quantification of crop gross primary productivity (GPP) is essential for studying carbon budgets in croplands and monitoring crop status. In this study, we applied a recently developed model, which relates crop GPP to a product of total crop chlorophyll content and incoming photosynthetically active radiation, for the remote estimation of GPP in two crop types (maize and soybean) with contrasting canopy architectures and leaf structures. The objective of this study was to evaluate performances of twelve vegetation indices used for detecting different vegetation biophysical characteristics, in estimating GPP of rainfed and irrigated crops over a period from 2001 through 2008. Indices tested in the model exhibited strong and significant relationships with widely variable GPP in each crop (GPP ranged from 0 to 19 gC/m 2/d for soybean and 0 to 35 gC/m 2/d for maize), however, they were species-specific. Only three indices, which use MERIS red edge and NIR spectral bands (i.e. red edge chlorophyll index, MERIS Terrestrial Chlorophyll Index and red edge NDVI), were found to be able to estimate GPP accurately in both crops combined, with root mean square errors (RMSE) below 3.2 gC/m 2/d. It was also shown that two indices, red edge chlorophyll index and red edge NDVI with a red edge band around 720 nm, were non-species-specific and yielded a very accurate estimation of GPP in maize and soybean combined, with RMSEs below 2.9 gC/m 2/d and coefficients of variation below 21%.